21032040 has 32 divisors (see below), whose sum is σ = 63096480. Its totient is φ = 5608512.

The previous prime is 21032023. The next prime is 21032059. The reversal of 21032040 is 4023012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87514 + ... + 87753.

It is an arithmetic number, because the mean of its divisors is an integer number (1971765).

Almost surely, 2^21032040 is an apocalyptic number.

21032040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21032040 is an abundant number, since it is smaller than the sum of its proper divisors (42064440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21032040 is a wasteful number, since it uses less digits than its factorization.

21032040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175281 (or 175277 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 21032040 is about 4586.0702131564. The cubic root of 21032040 is about 276.0326573413.

Adding to 21032040 its reverse (4023012), we get a palindrome (25055052).

Subtracting from 21032040 its reverse (4023012), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 21032040 in words is "twenty-one million, thirty-two thousand, forty".